help identifying lathe

If it may be a R and A then look at the Lathes UK website, for R and A lathes. There should be a lot of useful information there.

Howard

Hi Nick,

I anticipated the need to provide a decent power train for my lathe; I found a (used!) Myford Vee-pulley with 4 diameters going for a song on eBay, it has a key fitting on 3/4" I.D.

I ordered a 3/4" round steel rod and I will get some pillow blocks to support it. I was admiring the countershaft arrangement and want to build something like the one belonging to your father, I just wondered if there are any drawings available?

Any info on this setup would be great.

ALSO.....

Possibly too many questions here below, but I really would be grateful if anyone feels inclined to answer?

* I have a load of gears that came with it but the I.D. is smaller than on the lathe... I wonder if they were from something else?

* Also there is a lever at the back, presumably to do forward/reverse but it 'locks up' the transmission when engaged, I do not think it is set up right, something is wrong here. Its not very clear in the photos but both cogs (either side of the lever) engage with cogs the other side at the same time, hence the lockup situation. Maybe I should remove on of the cogs? I can't figure it out.

* You will see it has a mechanism for operating the main screw with an escapement type arrangement. I have not seen this on other lathes. Any other photos/examples/notes on this mechanism?

*what type of tool holder accessory is best to use to replace the crude toolholder there is currently? I think I might be able to replace the vertical threaded rod to a longer one and get something from Banggood?

e.g. https://www.banggood.com/Machifit-250-000-Cuniform-GIB-Type-Quick-Change-Tools-Kit-Tool-Post-250-001-010-Tool-Holder-for-Lathe-Tools-p-1434251.html?akmClientCountry=GB&p=9B120818168716201801&custlixnkid=720029&cur_warehouse=UK&ID=515563

* One more thing, I tried getting the main shaft out but am a bit frightened to use much force on removing existing cogs... anyone?

Edited By James Tregaskis on 29/06/2021 17:33:10

The lever on the back that locks the transmission is not to reverse, but most probably to engage back gear. the reason that everything locks is that you have effectively engaged two gears, of different ratios at the same time.

You need to find how to disengage the bull wheel (The gear that is locked to the pulley ) so that the drive can be pulley to small gear pinion, to large gear on back gear shaft thence to small gear on back gear shaft and back ton the bull wheel and mandrel..

Most probably a grubscrew in the bottom of one of the vees in the pulley.

Probably safest to remove the grubscrew completely and put it in a safe place, rather than leave it in and chance it being thrown out at some time when back gear is being used.

Back gear will reduce the speed of the mandrel by a factor of about 6, and provide extra torque.

It is a very useful feature when working, or screw cutting upto a shoulder, in that it gives you more time to disengage the feed, or stop the mandrel by slackening the belt. Saves a lot of damaged tools and workpieces, ,believe me!

The mechanism to reverse the feed, probably by the Leadscrew will be the tumbler reverse. This is two identical pinions, meshed together and mounted on a lever which allows one pinion to drive the geartrain directly, or when the lever is moved, via the second gear (Which acts as an Idler and so reverses the direction of rotation of the gear train relative to the mandrel.

My preference is for the "old fashioned" 4 way toolpost. Reputed to be more rigid that a QCT. Not having one, cannot confirm or deny. But the more rigid the tool set up, the better things will be from the point of surface finish and accuracy.

Biased, 'cos I have one at the front and another at the back!

For a lathe of that age, HSS would be my advice on tooling. You learn how to grind tools, is cheaper than carbide. (The lathe was designed before carbide tooling became common place, so will lack the speed and rigidity to get the best out of it. Intended for heavy industrial machines where time is money )

My favourite HSS tool is the Tangential Turning Tool, either home made, (MEW has published at least two designs, in the past ) or the Diamond tool from Eccentric Engineering. With only one face to grind, sharpening is quick and easy.

A 1/4" toolbit cost about the same as a carbide insert and will outlast a single carbide insert. Plus, as I keep saying, you can regrind at 8:00 on a Saturday night, when a chipped carbide tip ceases to be of any use.

Before anyone complains of ignorant bias, I also use carbide tips, for roughing, boring and screwcutting!

The "escapement type arrangement" looks to be a detent for indexing, using a changewheel to provide the means of dividing.j

HTH

Howard

Hi James, those gears as if they are Drummond screw cutting change gears for the leadscrew with the two holes in them for driving them. The gears that are locking together are backgears for screw cutting, when in use, you need to release the grub screw on the V pulley, to allow that to turn on the spindle, it will then drive the spindle at a slower speed through those back gears.

Regards Nick.

As Nicholas says, it looks as if the changewheels can be driven, or compounded by pins engaging in the holes min the gears.

This is a similar arrangement to that used on the early Myford ML Series (1, 2, 3 and 4 ) where a 3/32" pin locates in a hole, drilled half way through the gear, and the driving collars that go on the Mandrel and Leadscrew. The driving collars on those machines are secured to the mandrel and Leadscrew by 1/4 BSF grubscrews, and the pin provides the drive between gear and driving collar.

If you think that the lathe is a R and A, go to Lathes UK website and study the pages on the R and A. You will learn a lot about your machine. from there, and understand its construction and operation much better.

Howard.

And thank you Howard and Nick,

Yes, I have a learning curve to navigate, no question. Not ashamed to say it. Anyway, after all, I graduated with MFA (Master of Fine Art) Computational Art in 2019, and I am 67!

So old dog...etc. Anyway, I bought "The Amateurs Lathe", "Mini Lathe and "Tool Projects" and "The Mini Lathe"... also the Whitworth documentation from Lathes.co.uk and I am scouring the web for more.

I am getting into the wealth of info here not to mention your replies are really helpful.

Emgee, the brilliant chap is helping me kit out the chuck.

Its so good here and so friendly, thanks all! Keep em coming, I will post progress here, if that's OK.

My website is tregaskis.org (but scarce on the engineering side!), I will put some relevant posts there when things gel a bit more with the Randa.

cheers!

James